System software is a program that manages
and supports the computer resources and operations
of a computer system while it executes various tasks
such as processing data and information, controlling
hardware components, and allowing users to use
application software. That is, systems software
functions as a bridge between computer system
hardware and the application software.
System software consists of four types of programs:
resources, provide an interface between users and
the computer, and run applications.
2. Utilities perform specific tasks related to managing
3. Device drivers are specialized programs that allow
particular input or output devices to communicate
with the rest of the computer system.
4. Language translators convert the programming
instructions written by programmers into a
language that computers understand and process.
Functions of operating system:
1.Managing resources. These programs coordinate all
memory, processing, storage, and devices such as
printers and monitors.
2. Providing users interface. Users interact with
application programs and computer hardware
through a user interface.
3. Running application. These programs load and run
applications such as word processor and
Mac OS is a series of graphical user interface-based operating systems developed
by Apple Inc. for their Macintosh line of computer systems. The original version was
the integral and unnamed system software first introduced in 1984 with the original
Macintosh, and referred to simply as the "System" software.
Unix was also
system. It is
Most essential programs of utilities:
• Troubleshooting that recognize and correct problems, ideally
before they become serious.
• Antivirus programs that guard your computer against viruses
or other damaging programs that can invade your computer
• Uninstall programs that allow you to safely and completely
remove unneeded programs and related files from your hard
• Backup programs that make copies of files to be used in case
the originals are lost or damaged.
• File compression programs that reduce the size of files so they
require less storage space and can be sent more efficiently
over the internet.
Whenever a new
device is added to a
computer system, a
new device driver must
be installed before the
device can be used.
- is all the computer software that causes a computer
to perform useful tasks (compare with computer viruses)
beyond the running of the computer itself. A specific
instance of such software is called a software
application, program, application or app.
• The term is used to contrast such software with system
software, which manages and integrates a computer's
capabilities but does not directly perform tasks that
benefit the user. The system software serves the
application, which in turn serves the user.
• using a computer to create, edit, and print documents. Of
all computer applications, word processing is the most common. To
perform word processing, you need a computer, a
special program called a word processor, and a printer. A word
processor enables you to create a document, store it electronically on
a disk, display it on a screen, modify it by entering
commands and characters from the keyboard, and print it on a
1. Spelling checker
2. Font and Font Size
3. Center Aligning
4. Word Wrap
5. Character Effects
6. Grammar Checker
• is an interactive computer
application program for organization and
analysis of data in tabular form. Spreadsheets
developed as computerized simulations of
paper accounting worksheets. The program
operates on data represented as cells of an
array, organized in rows and columns.
• Integrated packages is a single program that
provides the functionality of
processor, spreadsheet, database manager
and more. They are popular with many home
users are sometimes classified as personal or
home software. Less expensive than
purchasing several individual application
programs and simple to use.
Computer data storage, often
called storage or memory, is a technology
consisting of computer components
and recording media used to retain
digital data. It is a core function and
fundamental component of computers.
The central processing unit (CPU) of a
computer is what manipulates data by
Primary storage (or main
memory or internal memory), often referred
to simply as memory, is the only one directly
accessible to the CPU. The CPU continuously
reads instructions stored there and executes
them as required. Any data actively operated
on is also stored there in uniform manner. A
random-access device allows stored data to be
accessed directly in any random order.
Secondary storage (also known as external memory or
auxiliary storage), differs from primary storage in that it
is not directly accessible by the CPU. The computer
usually uses its input/output channels to access
secondary storage and transfers the desired data
using intermediate area in primary storage. Secondary
storage does not lose the data when the device is
powered down—it is non-volatile. Per unit, it is
typically also two orders of magnitude less expensive
than primary storage. Modern computer systems
typically have two orders of magnitude more
secondary storage than primary storage and data are
kept for a longer time there.
Hard disk drive
is a data storage device used for storing and
retrieving digital information using rapidly
rotating disks (platters) coated with magnetic
material. An HDD retains its data even when
powered off. Data is read in a randomaccess manner, meaning individual blocks of
data can be stored or retrieved in any order
rather than sequentially.
Basic types of hard disk:
An internal hard drive is a hard drive that resides inside
the computer. Most computers come with a single internal
hard drive, which includes the operating system and preinstalled applications.
An external hard drive is a typically connect to a USB or
FireWire port on the system unit, are easily removed and
effectively provide an unlimited amount of storage.
• Flash memory is an electronic non-volatile computer storage device
that can be electrically erased and reprogrammed.
• A floppy disk, or diskette, is a disk storage medium composed of a
disk of thin and flexible magnetic storage medium, sealed in a
rectangular plastic carrier lined with fabric that removes dust
• Magnetic tape data storage uses digital recording on magnetic
tape to store digital information. Modern magnetic tape is most
commonly packaged in cartridges and cassettes. The device that
performs actual writing or reading of data is a tape
drive. Autoloaders and tape libraries are frequently used to
automate cartridge handling.
• A punched card, punch card, IBM card, or Hollerith card is a
piece of stiff paper that contains digital information represented by
the presence or absence of holes in predefined positions.
• Special service sites on the Web provide users
with storage. This storage is called an Internet
hard drive. Advantages of Internet hard drives
compared to other types of secondary storage
include low cost and the flexibility to access
information from any location using the